Before you sign up for that tablet data plan, why not just your phone as a mobile hotspot instead?

Mobile hotspot — sometimes called wireless tethering — is a feature on most smartphones that lets you share the phone’s data connection with other Wi-Fi devices. Essentially, your phone creates its own wireless network, providing data to nearby tablets, laptops, e-readers and iPods. It can even connect to multiple devices at the same time, so it’s great to have for family road trips.

Here’s the best part: Depending on your wireless carrier and current plan, you may be able to use your phone’s mobile hotspot feature at no extra charge. And even if you have to pay, you’ll likely save over $100 per year by using mobile hotspot instead of a separate tablet data plan.

While mobile hotspot isn’t new, I’m always surprised when people tell me they had no idea it exists, and assumed they had to pay for a separate tablet data plan. Then again, this shouldn’t a big shock given how carriers aggressively market their tablet data plans instead of educating customers about this cheaper alternative. If you’re just now being enlightened, here’s what you need to know:

How Much Does Mobile Hotspot Cost?

It depends on the carrier, but I’ve broken down the four major ones below, along with their prices for tablet data plans.

Verizon Wireless: Mobile hotspot is included with the carrier’s shared data plans, whereas a tablet-only plan would cost you $10 more per month. For all other plans, mobile hotspot costs $20 per month and provides 2 GB of additional monthly data. The same $20 gets you just 1 GB per month if you sign up for a separate tablet plan. For infrequent use, Verizon also offers $5 day passes with 300 MB of data.

Sprint: Mobile hotspot use starts at $10 per month for 1 GB, regardless of whether you have an unlimited smartphone data plan. If you do have an an unlimited smartphone plan, you can tack on 5 GB of hotspot use for $30 per month. By comparison, Sprint’s tablet data plans cost $15 per month for 300 MB and $30 per month for 3 GB.

T-Mobile: Mobile hotspot is free with all Simple Choice plans. Any data you use counts against your monthly limit, except for unlimited plans, which get 2.5 GB of hotspot use per month. For tablet users, T-Mobile provides 200 MB of free tablet data per month, but charges $20 per month for 500 MB and $30 per month for 2.5 GB.

Mobile Hotspot vs. Tablet Data Plan

The clear advantage with a mobile hotspot is that it’s usually cheaper, not just in monthly fees, but in the up-front cost of buying a Wi-Fi-only device. Apple, for instance, charges $130 more for an LTE-enabled iPad, which you don’t need if you’re just using mobile hotspot. Factor in the cost of data, and you’ll save hundreds of dollars over the life of the tablet. You also get the flexibility of being able to connect any tablet, laptop, iPod or e-reader instead of just a single device. (Apple’s iPad, however, can act as a mobile hotspot if it has its own data plan.)

Still, mobile hotspot has some disadvantages. Turning it on can drain your phone’s battery life, so it’s not ideal for hours of use away from a power source. (You could, however, invest the money you’ve saved in a spare battery pack for your phone.) A tablet with its own data plan also lets you get online immediately, without first reaching for your smartphone. For people who spend hours working on their tablets without Wi-Fi coverage, these conveniences could be worth the money. But if you’re just connecting during the occasional road trip or airport layover, mobile hotspot is the way to go.

A Word About AT&T Unlimited Data Plans

AT&T doesn’t offer mobile hotspot to users who are grandfathered into unlimited data plans. Is it worth switching to a limited plan to get mobile hotspot? That depends on how much data you already use per month, and how much you plan to use with your tablet.

Someone who’s burning through 10 GB every month should hang onto that plan for dear life, but there’s no reason to keep the plan if you’re not taking advantage of it. The one exception is if you can limit your tablet use to 250 MB per month, thereby qualifying for AT&T’s $15 per month plan. That’s not a lot of data to work with, but it’s cheaper than switching to a limited plan with the $20 per month tethering charge.

How to Set Up Mobile Hotspot

To sign up for mobile hotspot use, you’ll likely have to call your wireless carrier or change your account settings online. But once that’s taken care of, turning your hotspot on is pretty easy.

Apple

For iPhone users, go to Settings, and tap “Personal Hotspot” near the top of the menu, then flip the switch next to “Personal Hotspot.” Optionally, you can change the Wi-Fi password to something more memorable from this screen.

The name of the wireless network will be the same as name you’ve given your phone (“iPhone” by default). You can change the name of your phone by going to Settings > General > About > Name.

Android is just a little trickier because the Settings app can vary by phone, but here are instructions for recent phones from the major brands:

Samsung

On Samsung Galaxy phones, go to “More Settings” under the “Wireless and Networks” section of settings, then flip the switch for “Mobile Hotspot.” You can also change network settings by tapping on the words “Mobile Hotspot.”

On LG phones, go to the “Networks” tab in settings, then tap “Tethering & networks” at the bottom. Flip the switch for “Mobile Hotspot,” or tap on the words to change your network settings.

On HTC phones, tap on “More” under the “Wireless & Networks” section of settings, then tap on “Mobile network sharing.” You’ll see a check box for “Portable Wi-Fi hotspot” and another option for Wi-Fi hotspot settings.

Once you’ve turned on mobile hotspot, you can connect to it from your tablet or laptop just like any other wireless network. Congrats: You’re not exactly sticking it to the man, but at least you’re paying less for the same connectivity.